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The velocity and momentum of an object is 1000 cm/s and 10,000 gcm/s. What is the kinetic energy of the object?

1If by some phenomenon the earth contracts to one half of its present size while keeping all the other variables constant then gravitational potential energy of an object of same mass kept at the same distance from the surface of earth will become:

A body of mass m moving with a velocity v is continually accelerated in the direction of its motion due to a force F that acts at some angle x with the direction of its motion. The kinetic energy of the car is plotted against displacement d covered by the car. The slope of the graph thus obtained will give us:

A car is travelling at a constant speed and the driver suddenly opens a nitro thrust which increases the kinetic energy of the car by 4 times. Speculate how the momentum of the car will change.

A labourer has a cupboard 5 metres high and wants to stock six bricks over the top rack of the cupboard one next to the other. Each brick is 2 kg and 5cm thick. Find the work done by the labourer.

A body accelerated from 0m\s to 10m\s and the change in KE is E. What will be the change in KE when its velocity is changed by an equal amount again?

A fisherman fishes a fish of 250 grams from a 1.8 m deep water. The fisherman pulls the string so hard upon catching the fish that the fish gains a speed of 1.1 m/s by the time it reaches the surface of water. What is the total energy gained by the fish? (relative to the pond floor)

A bar magnet is lying with its north pole next to the south pole of another bar magnet and a force of attraction is present between the two magnets. A student pulls the two magnets apart. The potential energy of the magnets is increased or decreased?

Calculate how much gravitational potential energy is lost by an aircraft of mass 80,000 kg if it descends from an altitude of 10,000 m to an altitude of 1000 m.

Which of the following has greater kinetic energy?
■ A 20-tonne truck travelling at a speed of 30 m s −1
■ A 1.2 g dust particle travelling at 150 km s −1 through space

If mass and speed of an object are doubled, the kinetic energy and momentum will be (respectively):

A book lying on a table in a room on the second storey has some potential energy relative to the floor of the room. The same book has a much higher potential energy relative to the floor of a room on the first storey. This fact proves that:

A mass-spring system has maximum potential energy when:

If mass of a body is doubled and kinetic energy becomes half, what happens to the velocity of the body?

A body of mass 10 kg has a potential energy of 196 J. What is its height?

When work done is posiive, kinetic energy will:

A car weighing 100 kg is moving twice as fast as a car weighing 200 kg. The kinetic energy of 100 kg car is:

When two protons are brought closer, the potential energy between them

A mechanical watch stores:

Two bodies having same kinetic energy have velocities in the ratio of 4:5. What will be the ratio of their masses?